Tool retainer for pneumatic hammers



TOOL RETAINER FOR PNEUMATI'C HAMMERS July 17, 1928.

J. M. BUTLER ET AL TOOL RETAINER FOR PNEUMATIC HAMMERS Filed Sept. l0, 1925 2 Sheets-Sheet f alg( Mil/fax J' tion `for stretchingl Patented uliil'y l?, i923.,

g reime JOHN M. BUTLER AND A. TORSON, OF C IPIAGO, ILLNGIS, ASSIGNORS TO KING- i ENEUMATIC TOOL COMPANY.

TOOL RETAINER FOR PNEUMATIC HAMIVEERS.

Application led'septeniber i0, 1923. Serial No. 961,963.

nectinfiii` a removable tool AWith the hammer barrel in such ainannerthat the tool ivill be yretained reliablyfagainst accidental detachment While being readily removable when desired.

The invention will be' clearly understood by reterence to one illustrative embodiment thereof shown in, the acconipanying draivings.

In said drawings:

Fig'. l is a side elevation ot a conventional type of pneumatic 'hamii'ier having means embodying' the invention. 'In this ligure. a portion of l'the hammer barrel is shown broken aivayA to reveal interior parts.

Fig. 2 is an enlarged elevation oit the ioi- Ward terminal `portion of the hammer7 this being the portion equipped with the improved means referred to. Fig. `8Y is a cross section itaken on the line oi' Fig. 2,loolringV in the direction ol `the arrows and showing parts in end elevation. Y y

Fig. @shows the same parts as in 2 v'ieived- 'from the bottom.

Fig'. shows the same parts -as in Fig. 2 viewed .ionithe top.

Fig. 6 is a. longitudinal vertical section of the parts shown in Fig'. 2.

'I Fig. f? is an elevation similar to Fig. 5 but representineY the Working tool in a posithe connecting;V means.

Fin'. 8 is a side elevation of the parte slioivn in Fig'. 2, representingl a manipulation to permit ready1 detachment et the-tool.

Fig. 9 is atop view of the parts, showing the tool released from the retainer.

In the drawings, l denotes the cylinder or barrel eta pneui'i'iatic hammer.

The pneumatic hammer selected for illustration lias an V`inlet at l- 'tor admission of compressedxair through the handle, While the'exhaust air discharges through openings in a so-called exhaust detlecl'or 7. The handle may `contain a throttle valve controlled .liv thel lever 6. 'lhe cap-like handle base 5, screwed uponl the barrel, encloses' the hammer valve head. The hammer piston, reciprocating in the barrel, is slioivn at 8. All of these parts will. be understoor-l by .those skilled in the art.` y y The hammer carries a Working tool, represented bv a rivet set 2. The shank oit' the rivet set is shown vfitted in the center bore or opening' in the nose olthe ',bariel, andL receivesthe iii'ipacts delivered by thehainmer piston 8. On the head ot the Vrivet set is a lange lO presenting' a shoulder 9 [which enters into a 'function presentlyto bede-' scribed.

The tool orrivct set '2, While capable ot' necessary play or longitudinal n'iovement under the action oi theA hammer piston, is removably connected lwith and held in proper operative relation to the barrel b v a tOOLretaining device indicated at 3 in Fig. l and shown `more fully in the reifnaining figures `of the drawings.v i

This device may be considered as comprisingthree `functional parts, naniely,-an attaching member 12 by which the device is u secured to the hammer barrel; a retaining member 15 arranged in *front of the flange 10 ott' the tool andadapted to form a stop or abutment for Vthe shoulder 9, so asA to limit the outward movement of the tool; and an intermediate which the retaining' membeiyl is supported in proper relation to the tool 'from the 'atcaching means with capacity ot being flexed in relation to the barrel.

The attaching member l2 is shown as a still' contractile ringt which is forced over the nose of the barrel and secured thereto, `inv this instance, by engagement with an annular resilient connection 13y by.

fifi

grooif'c 2O on the barrel. Advantage'may be taken of. a taper or bevel 21 onthefnose of the barrel forexpending the ring to force it on ythe barrel and allow itv to snap into thel groove. llfherethe nose of the barrel is so tapered or bevelled, the ring. be made' ot somewhat smaller diameter 4than otherend of said member 15 is bent forwardly as indicated at 19 for a purpose which will presently appear'. y

The connectingmember 13 is shown as an extension from the ring 12, having approximately the forni of a spiral, and appropriately curving toward the axis of the hammer so as to hold the retaining member 15 closely around the tool head. (See Fig. 3.

The retaining device as a whole may be constructed from an integral strip of spring steel, of appropriate form', size and stifl'- ncss for the purposes in view. `Such a device may advantageously be made from stout spring wire, flattened by rolling. The drawings are intended to illustrate a device so formed.A

The flattened wireA forming thel device may bebent inA such a manner that the wider fiattened faces of the attaching ring 12 and curved retaining arm 15 are at the sides of these members, or in other words in planes transverse of the axis of the hammer and tool. This increases the transverse sti ff'- ness of these parts, while their flattened sides and resulting edges coactI eifectually with the walls of the groove 20 to resist accidental displacement of the ring 12, and with the tool fiange lOto produce a biting action thereon when force is applied tending to separate the tool from the body. In other words, a flat-sided formation of the attaching ring increases its' resistance to displacement from the groove; while a Hat-sided formation `of the` curved retaining arm 15 promotes its capacity to retain the tool, and especially its resistance to disengagement` from the tool by oamming action of the shoulder 9 or flange 10 against the retaining arm.`

In operation, the thrust of the tool flange 10 against the retaining arm 15, under a force tending t0 separate the tool from the hammer barrel, will tension the retaining device, as represented in Fig. 7 of the drawings. The forced distention and tensioning of the connecting portion 13 of the retaining device will tend to contract the device around its axis; or draw the retaining arm 15 tightly t0 the tool head, promoting its effectual coaction with the shoulder 9 in the flange 10 of the tool. Thus the harder the force, the harder the retaining device holds the tool, ensuring its effectual retention under all ordinary conditions. y

It will be observed that the retaining de- Vice is connected to the hammer barrel much more securely than to the rivet set or tool which is removably held in operative position with capacity for longitudinal movement, within the limits allowed by the spacing of the retaining arm 15 from the nose of the barrel. Vith the specific construction shown, it would obviously require a much greater force to detach the kretaining device from the hammer barrel than to detach the rivet set fromthe retainer, since the portion of the device attached to the barrel (i. e. the attaching ring 12) extends practically all around and grips the barrel, be-

tically as a permanent attachment, While the rivet set or other tool is releasably retained, though eliectually enough to prevent. dropping out of the rivet set or its accidental detachment by any ordinary force. In fact, for the purposes in view, the retaining device should be, and one constructed as described is ordinarily, stiff enough to resist etfectually any effort to pull out the tool by mere manual force, unless such pulling be accompanied by some distortion or adjustment of the retaining device as hereinafter explained. Hence the yproper retention of the tool under ordinary conditions isensured, the retaining device being so stiff that its capacity will not be seriously imiiiaired by the vibrations of the hammer or by repeated stressing of the device during removal and insertion of tools.

Assuming the retainer to be attached to the hammer barrel, thek rivet set or tool may be attached byv inserting the end of its shank in the bore of the barrel, as indicated in Fig. 9, and then driving in the tool by a sharp blow or quick manual thrust, causing the retaining arm to spring and snap past the tool flange 10, so as to lie on the forward side of said flange as 'shown in In this action, the compressive stressing ofthe retaining device tends'to expand or move the retaining armY 15 outwail-diy sufficiently to allow the tool flange 10 to pass it. This outward displacement of the arm 15 may be facilitated by engagement of the flange 10 with the bent terminal or finger 19 before its engagement with the arm. .For example, as indicated in Fig. '9, the edge 17 of the flange 1() may ride on the edge 18 ofA the linger 19, thereby moving the arm 15 outward sufficiently to allow further displacement of said arm and movement of the flange 10 past the retaining arm by a slight blow or quick thrust. vThe provi- V sion of such finger 19 is therefore desirable in cases where the retaining arm 15 may be so stilfly held, 0r present such anv extent of flat surface in opposition to the flange 10, to oppose seriously Vthe manual insertion of the tool or to require an undesirably severe blow for that purpose.

Ai l.)

the work.

agora-evo Ato drive through; 'lhe'ejectment may be eiiected without danger 'of detachment of the tool retainer' from the hammer barrel, by virtue oi' the secure retention of the latter on the barrei, and because, as already indicated, the orcefrequired to detach theV tool i'romfthe retainer is much less than that which would'berequired Vto pull the retainer from the barrel. 'I

A capacity for quick 'ejectment oi? `the working tool is dcsi1'able,'since in the use of pneumatic hammers 'it' may :be frequently necessary to substitute one working tool for another. For exampilda man operating a pn'eun'ia-tic riveting 'hammer may have occasion to use, while on the same work, a number of diiierent rivet sets adapted for loperation on rivets of diii'erent sizes. TheV rivet set being` hot after use, it would be impracticable for that reason, as well as on account oit loss ot time, to attempt. to remove the tool from the retainer by manual manipulation. VJitli a retainer of the illustrative construction, the operator of the hammer may eject a rivet set or other tool at a moments notice, by shooting it from the hammer, and. then quickly insert a substitute rivet. set or tool in the retaining device, which remains in its proper position on the barrel.

In other circumstances, it may be necessary to detach the rivetset or tool manually, as for example where the pneumatic hammer is disconnected from the compressed air supply, and happens to have been put away without ejecting the tool, as previously stated, a retainer of the construction described would ordinarily be too stiffto permit removable of the tool by mere manual force, unless the retainer be distorted. In the event of a mere attempt to pull out the tool, the retaining device and especially the intermediate portion 13 will be strained or tensioned, with the etiect of inwardly constracting the retaining arm 15, whichl causes the latter to hug or grip the tool head all the tighter. However, a means for ready manual release of the tool, when necesary, is provided in the illustrative structure.

Such manual release may be accomplished byv a slight adjustment or'manipulation O the retaining device, indicated in Fig. 8 of the drawings. This adjustment consists in portion lto cam on the `i'ront lwafll 'of' gro'ove 20J and lit't the `contig ous Iend ip rrdisplacing from the g cove .20 the end of ithe attaching ring l2 contiguous with the connecting vvporti-,on The portion ol the ring ed to may vbe readily 'displaced hy, eeft the thumbs o'if the iope'rato'r while .1 -tlie `hanmie'r barrel his hands. his :capacity i'or displacement isincident the Iexiten'si'o'n ot the connecting member 13 from the attaching ring. A forward pressure 'on the fpor'tion of the connecting'memher` i3 a-c'ljfacentto 't'hle barrel will cause said 1 Vtio-'n ofthe attaching ring 12 out ofthe 'g-roo've, as shown lin Fig. TS.v "Such displaceiiientis accompe ied byfa sufliicient 'displaceinent'of the portion 'of the retaining device encircling the `tool head astopermitthe ytool to be withdrawn by a sharp pull, in which lwithdraw'al,the flange snaps past the retaining arm 515. Vfllhe rebound 'ofthe retaining armasthe A:toolis vdrawn out willusu'a'lly cause the' ,displaced 'endv oi' the attaching ring to reseat in the groove, under 4the natlu'ra'l` temleu'cyv voft the device I-t'o ,resume its fiorini I i' i 'i kThe rivet fselt or-tool ymay be-otherwise manually detached, tor instance by prying the retaining arm l5 'away from the head of the tool and over the flange 10, while withdrawing the tool; but this is a more diiiicult method of vdetachment than the one just described, and usually necessitates the use of a prying device. Hence in the case of a tool retainer of the advantageous character illustrated in the drawings, the method ot manual detachmentreferred to with referenceto Fig. 8, which'is easy' ot' accomplishment, is tov be preferred to that of prying the retainer to release the tool. Thetool retainer herein described permits adequate longitudinal play of the rivet set or otherl tool with which :it is associated, relieving the retainer ot the force and jar or' the'ha-mmer action, while it yieldably opposes and rebounds from such various stressing as it sustains. Itis adapted to withstand prolonged use without serious deteriowhich it is used. f A

it will be understood that the specific details of construction and arrangement of the illustrative structure may be modified to suit various requirements. Moreover it is lnot essential that all the features of the invention be used conjointly, since they may be advantageously used in various diierent combinations and sub-combinations.

Having described anembodiment of our invention, we claim with the 1. A tool retainer for pneumatic hammers comprising attaching means for connection ammer barrel and a still spring arm of approximately spiral curvature extending from said attaching means and having a continuing curved part adapted to closely hug the head of the tool carried by said barrel and to present a stop or abutment infront of a flange on said tool head, said arm adapted to be sprung` to permit attachment of the tool by a backward thrust of the tool with resultant compressive stressing of said arm tending'to expand or move said vstop outwardly to allow the tool flange to pass back of it,`and said semicircular stop part having a forwardly projecting terminal finger adapted to be engaged by the back 'edge of said tool lflange before engagement of said `flange with said stop part to facilitatethe outward displacement of said stop part or initiate its movementsulliciently to allow furtherdisplacement to permit backward passing of the tool flange under a backward thrust on the tool.

2. A tool retainer for pneumatic hammers comprising a unitary structure capable of flexing longitudinally of its axis and having attaching means for securing it to the hammer barrel and a retaining arm adapted to be sprung laterally `to permit attachment or detachment of the tool without disturbing said attaching means, said arm having a forwardly projecting terminal finger adapted to i jecting terminal finger and a spirally formed connecting means betweenl said retaining arm and attachingmean's, said structure vbeing capable of flexing longitudinally of its axis and laterallythereof when said linger ,is engaged by atool under stress of inserting the latter in said body and into holding relationship with said tool retaining arm.

In testimony whereof, we have signed our names to this specification.

JOHN M. BUTLER. HARRYA. TonsoN. 

